It's a changing of the guard at McKinley High as the reigning National Show Choir champions head back to school on
"Glee" Season 4. But not only has the dynamic changed within the school -- Tina (
Jenna Ushkowitz), Blaine (
Darren Criss) and the gang are all popular thanks to their title -- it's changed within the show, now that we go back and forth between Lima, Ohio and Rachel's (
Lea Michele) new life in New York City.

Criss tells Zap2it that he was shocked when he first found out how sassy Blaine would get. "I read the first episode and I was like what's going on?! Tina's really mean now, Blaine's really sassy. All these things are happening and I'm like, what happened to this nice guy we met in the first season?"

There's a simple explanation, though. "In high school people change, man. I don't know. Come senior year he's a different person. I don't know where it's going but he's going a little nuts."

Plus, Ushkowitz says the power trip won't last too long. "We get brought back down pretty quickly."

Tina is also humbled when the New Directions try to find their replacement Rachel and she realizes the group is full of star singers -- the same problem she faced before. The newbies aren't necessarily on her radar at first; she's more concerned with her fellow seniors.

"I don't think she looks at [the new kids] as competition just yet. Definitely Blaine, definitely Brittany, she's like 'Listen, we are the best, we deserve this stuff,' but I think she eventually gets to the point where she's like 'I'm getting these solos. Rachel told me I was getting these solos.'"

For all you Tina lovers out there, Ushkowitz acknowledges that Miss Cohen-Chang "usually gets the shaft," but rest assured: "She definitely gets more solos in the first, like, two episodes than she's had all last year, so yeah -- more Tina!"

Meanwhile, Michele tells Zap2it that although she's not in the choir room with the rest of her castmates, she's absolutely loving the show's divide between New York and Lima.

"Oh my God, I feel amazing. I am having the best time," she says. "This is already my favorite year so far. I love being in the new locations; I love being on the new sets -- they're so gorgeous. I love working with Chris [Colfer] and Cory [Monteith] and Dean [Geyer] and Kate [Hudson]. It's really amazing. I miss my Glee club, but I know [we'll be together soon]. I've already read a script where we're reunited."

"Glee" Season 4 premieres Thursday, September 13 at 9 p.m. on FOX. "Glee" Season 3 is available on DVD and Blu-ray in stores now.

Are you excited for the new "Glee" (and "The New Rachel")? How do you think the new locations and the new kids will shake up the show?